Documentation

Custom Feed and Entry Classes

Finally, you can extend the Zend_Feed classes if you'd like to
provide your own format or niceties like automatic handling of elements that should go into
a custom namespace.

Here is an example of a custom Atom entry class that handles its own
myns: namespace entries. Note that it also makes the
registerNamespace() call for you, so the end user doesn't need to
worry about namespaces at all.